Current regulator unaffected by radiation exposure and acceleration forces



June 13, 1967 ROMBERG 3,325,722

CURRENT REGULATOR UNAPFECTEI) BY RADIATION EXPOSURE AND ACCELERATIONFORCES Filed June 24, 1964 2 Sheets-Sheet 4 FIG. I

INVENTOR. EDGAR B ROMBERG BYW June 13, 1967 E. B ROMBERG 3,325,722

CURRENT REGULATOR UNAFFECTED BY RADIATION EXPOSURE AND ACCELERATIONFORCES Filed June 24, 1964 2 Sheets-Sheerv Dc CURRENT POWER AMPLIFEERSQURCE POWER AMPLIFIER OSCILLATOR OSCI L LATOR FIG. 2

INVENTOR. EDGAR B. ROMBERG ATTORNEY United States Patent CURRENTREGULATOR UNAFFECTED BY RA- DIATION EXPOSURE AND ACCELERATION FORCESEdgar B. Romberg, Whittier, Califi, assiguor to North American Aviation,Inc. Filed June 24, 1964, Ser. No. 377,622 7 Claims. (Cl. 323-1) Thisinvention relates to a new and improved current regulator for providinga constant current to a load.

In some applications, it is not practical to use conventional current orvoltage regulators such as zener diodes or other semiconductor typeregulators, because of the adverse effect of radiation exposure.Mechanical regulators are not subject to error due to radiation exposureas are semiconductor regulators, however, conventional orelectromechanical regulators are subject to error due to 1 accelerationforces.

Accordingly, an object of the invention is to provide a new and improvedcurrent source which provides a constant current yet is not subject toerror due to radiation exposure.

Another object of the invention is the provision of a mechanical currentregulator which will provide a constant current even with accelerationforces being applied thereto.

Still a further object of the invention is to provide a currentregulator which provides a constant current even i in the presence ofradiation exposure and acceleration forces.

A feature of the present invention is a current regulator having twomasses that are electromagnetically sup ported. In the presence ofacceleration, the current changes eifected in the two electromagneticsuspension means are in opposition. This opposing current change isutilized to provide a constant current source in the presence ofacceleration.

Other objects and advantages of the invention will become more apparentby a reading of the specification taken in connection with theaccompanying drawings wherein;

FIG. 1 illustrates an isometric view in cross-sections 01 a currentregulator embodying the invention; and

FIG. 2 illustrates a schematic diagram in block form of the controlcircuit utilized in the embodiment illustrated in FIG. 1.

The embodiment of the invention illustrated in FIG. 1

' includes a housing having a cylindrical outer wall 10. Mounted withinthe ends of the cylindrical wall 10 are two magnetic air gap assemblies.The magnetic air gap mounted in the upper end of wall 10 includes acylindrically shaped member secured to wall 10 and having a circularlydisposed recess 21 with a rectangular cross-section. Positioned in theupper portionof the recess 21 is a field coil winding 24 shown in FIGS.1 and 2. The recess 21 eifectively divides the main body portion 20 intoan outer ring shaped portion 23 and an inner cylindrical portion 22.Member 20 is magnetically conductive. The

' longitudinally of the cylindrical outer wall 10 and electricallyinsulated therefrom. Some suitable mount such as an elastic hinge (notshown) is employed between the inner side of wall 10 and plate 41.Extending upwardly from and transverse to base plate 41 is a cylindricalvoice coil support 43. Mounted on the cylindrical voice coil support 43is voice coil 44 as shown in FIGS. 1 and 2. The winding and direction ofcurrent through voice coil 44 is indicated by arrows in FIG. 2. As shownin FIG. 1, the cylindrical voice coil support 43 together with the voicecoil 44 mounted thereon are concentric with and extend upwardly throughrecess 21 into the circular magnetic air gap.

At the opposite end of outer cylindrical wall 10 is an other air gapassembly secured to the cylindrical wall 10. This assembly includes acylindrical body member 30 made of a magnetically conductive material.Extending downwardly through body portion 30 is a circularly disposedrecess 31 which is rectangular in cross section, as shown in FIG. 1.Mounted in the lower portion of recess 31 is a second field coil 34. Therecess 31 effectively divides the cylindrical body portion 30 into acylindrically shaped center portion 32 and outer cylindrical ringportion 33. The field coil winding 34 is wound and has current fiow inthe direction as shown in FIG. 2 so that the upper portion of thecentral cylindrical portion 32 becomes a north pole whereas the upperportion of the outer ring portion 33 becomes a south pole. Consequently,a magnetic air gap is established between portion 32 and portion 33.This air gap is circular in shape as can be seen from FIG. 1.

A second mass assembly 50 includes a base plate support 51 which iscircular in shape. The base plate 51 is mounted for pivotal movement onouter cylindrical wall 10 such as by an elastic cantilever pivot 52 madeof bronze, copper, etc. which is secured to base plate 51 and also tothe inner surface of cylindrical wall 10. Such a mounting is alsosuitable for mounting of the above described base plate 41 although itwill be understood that other suitable mounting can be utilized. Such amounting establishes freedom of movement of base plate 51 (as well asbase plate 41) in a direction axially of cylindrical wall 10. Inaddition, plates 41 and 51 are electrically insulated from walls 10.Extending downwardly from the lower surface of base plate 51 is acylindrical voice coil support member 53 which is concentric with boththe circularly disposed recess 31 and the circular base plate 51.Mounted on the lower portion of voice coil support 53 is a voice coil 54having a direction of winding and direction of current flow therethroughas shown in FIG. 2.

Connected between base plates 51 and 41 is a spring 49 which istensioned so as to tend to bring plates 41 and 51 towards each other.Spring 49 has one end connected to the center of the lower surface ofbase plate 41 with the other end secured to the upper surface of baseplate 51.

A pickoff assembly 60 is employed to sense movement of base plate 41 andincludes a capacitive plate 61 which is suitably insulated from cylinder10 by an insulator 62. Capacitive plate 61 is located upwardly of thebase plate 41. On the opposite side of the base plate 41 is anothercapacitive plate 63 which is mounted on the cylindrical wall 10 andinsulated therefrom by a suitable insulator 64.

Another similar capacitive pickoff sensor 70 is employed to sensemovement of base plate 51. Similarly, this assembly includes a firstcapacitive plate 71 and a second capacitive plate 73 which are locatedon opposite sides of base plate 51. Plate 71 is mounted on wall 10 andelectrically insulated therefrom by a suitable insulator 72. Plate 73 isalso mounted on wall 10 and electrically insulated therefrom a suitableinsulator 74. The above capacitive pickoffs are well known in the artand per se form no part of the invention.

A servo loop is employed which applies a current to voice coil 44 so asto maintain base plate 41 substantially undeflected with respect to itsenvironment regardless of acceleration forces being applied thereto. Aservo loop 90 is employed between capacitive pickup 70 and voice coil 54to maintain base plate 51 substantially undellected in its environmentregardless of acceleration forces. The two voice coils are supplied withcurrent con tinually due to the mechanical bias applied by spring 49.The voice coils 44 and 54 are connected in parallel and are in turnconnected in series with field coils 24 and 34 as well as the load 100.More specifically, the voice coils 44 and 54 are effective to applycurrent to the load in parallel relationship to each other. However, inthe presence of acceleration in a predetermined direction, the torquingcurrent of one voice will increase while the torquing of the other voicecoil will decrease. As a result of this relationship, the current sourcein voice coils 44 and 54 are effective to supply a constant current to aload regardless of acceleration forces or the direction of such forces.

As shown in FIG. 2, the capacitive plates 61 and 63 are connected toopposite ends of the center tap primary of a balancing transformer 81.The output of the secondary of transformer 81 is applied to an amplifier82. This amplifier 82 is in turn connected to a demodulator 83 which isconnected to a DC power amplifier 85. Amplifier 85 is connected toterminal 45 of coil 44. An oscillator 84 is connected to demodulator 83and also to conducting base plate 41.

Capacitive plates 71 and 73 are connected to opposite ends of a groundedcenter tap primary of a balancing transformer 91. The secondary oftransformer 91 is applied to an amplifier 92 which has its outputconnected to a demodulator 93. Demodulator 93 is connected to the inputof a DC power amplifier 95 which in turn is connected to one endterminal 55 of voice coil 54 as illustrated in FIG. 2. Oscillator 94 isconnected to demodulator 93 as well as to conducting base plate 51.

For purposes of illustration, the B+ supply or current supply for poweramplifiers 85 and 95 is illustrated separately as a current source 86.This is done to facilitate explanation of the invention, and it will beunderstood that all other B+s for the demodulators, oscillator andamplifiers are to be include-d within the respective schematic box asillustrated.

As stated above, power amplifier 85 is connected to terminal 45 of avoice coil 44 to provide current through the voice coil as illustratedin FIG. 2. The other terminal 46 of the voice coil 44 is connected toterminal 25 of field coil 24 to provide current in the directionindicated by arrows. Another terminal 26 of field coil 24 is connectedto terminal 35 of field coil 34 to provide current in the directionindicated. The other terminal 36 of field coil 34 is connected to load100.

Power amplifier 95 is connected to terminal 55 of voice coil 54 toprovide current in the direction as indicated in FIG. 2. The otherterminal 56 of voice coil 54 is connected to terminal 46 and terminals25 of voice coil 44 and field coil 24 respectively.

In the absence of external acceleration forces, the spring 49 willeffect, through servos 80 and 90, equal servo current in voice coils 44and 54. Since these voice coils are connected in parallel electricalconfiguration, the sum of these two currents will be the current throughfield coils 24 and 34 as well as through load 100. In the presence ofacceleration, the current in one of the two voice coils will increasewhile the current in the other voice coil will decrease so as to providea sum current substantially equal to the sum current when noacceleration is present.

The servos 80 and 90 per se are in principal conventional torquingservos to maintain base plates 41 and 51 substantially undefiected intheir environment. More specifically, these servos maintain base plate41 equidistant between capacitive plates 61 and 63 whereas torquingservo 90 maintains base plate 91 equidistant between capacitive plate 71and 73.

Oscillator 84 as stated above is connected effectively between baseplate 41 as shown in FIG. 2, and the center tap of the primary oftransformer 81. The primary of this transformer together with thecapacitance between plate 61 and base plate 41 and the capacitancebetween capacitive plate 63 and base plate 41 form a bridge. When baseplate 41 tends to move in presence of acceleration forces, this bridgewill tend to unbalance so as to provide a signal to amplifier 82 andthence demodulator 83. The oscillator 84 is applied to demodulator 83 asa reference to determine phase and amplitude of necessary torquecurrent. The output of demodulator 83 is applied to a DC power amplifierhaving a current source 86, which feeds the voice coil 44. As in theconventional type servo, an acceleration or forces in one direction orthe other on the base plate 41 will result in a torquing current beingapplied to voice coil 44 from power amplifier 85. This torquing currentwill maintain the base plate 41 equidistant from plates 61 and 63, andhence substantially undeflected with respect to its environment.

The servo 90 is identical to servo with capacitive plate 71 and 73 beingconnected to opposite ends of the center tap primary of balancingtransformer 91. The secondary of transformer 91 is applied to amplifier92 whose output is connected to demodulator 93. Demodulator 93 isconnected to DC power amplifier 95 so as to apply a current in thedirection indicated to voice coil 54. Oscillator 94 is electricallyconnected to base plate 51 as well as demodulator 93. When a force oracceleration is apapplied to base plate 51, a torquing current willresult which is applied to voice coil 54 as a restoring force on baseplate 51. The operation of this servo 90 is similar to servo 80 with thebridge including the primary of transformer 91 together with thecapacitance between plates 71 and 51 and the capacitance between plates73 and base plate 51.

As stated above, the spring 49 tends to move base plates 41 and 51towards each other. This results in an equal torquing current in voicecoils 44 and 54. Since coils 44 and 54 are connected in parallel, thesum of these two currents thence is the current flowing through fieldcoils 24 and 34 as well as load 100. Effectively, the cur rent source isthe 13+ or collector current source 86 of power amplifier and 95. Therewill be understood that a single current source is shown althoughobviously more than one can be utilized at a period.

If an acceleration or force tends to move base plates 41 and 51upwardly, the servo 80 will decrease the current in voice coil 44whereas the servo will increase the current in voice coil 54. If anacceleration tends to move plate 41 and 51 downwardly, servo 90 willdecrease the current in voice coil 54 whereas servo 80 will increase thecurrent in voice coil 44. Since coils 44 and 54 are connected inparallel, a relatively constant current will be applied to field coils24 and 34 as well as load through voice coils 34 and 54 with or withoutthe presence of acceleration. Hence, a relatively constant current isapplied to maintain a relatively constant strength magnetic air gap soas to aid in maintaining a constant current to load 100.

It will be understood that when a conventional B+ current supply isemployed as current source 86, the current flow through coils 24, 34, 44and 54 will always be in the direction as shown by the arrows on thesecoils in FIG. 2. Hence, the spring 49 must preferably be strong enoughto overcome forces of acceleration so as to continually maintain suchunipolar current in both coils 44 and 54. Otherwise, the currentregulation would deteriorate.

The voice coils 44 and 54 should create the same magnetic force for agiven current. To achieve this, the voice coils 44 and 54 of theembodiment illustrated are identical except for .the direction ofwinding as shown in FIG. 2. Likewise, the field coils 24 and 34 areidentical except for the direction of winding also shown in FIG. 2, soas to create the same or equal magnetic fields with the same or equalcurrent.

It F is the spring force, F is force of external accelera- Where i and iare the current in voice coils 44 and 54, respectively, Therefore Thisspring force is a constant. Thus, it can be seen that the sum of thecurrents in voice coils 44 and 54 is constant despite the presence ofacceleration. Also, it will be understood that the spring constant of 49will determine the total current.

Although this invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample only and is not to be taken by way of limitation, the spirit thescope of this invention being limited only by the terms of the appendedclaims.

I claim:

1. A current regulator comprising a first mass mounted for freedom ofmovement normal to a predetermined plane, a second mass mounted forfreedom of movement normal to said predetermined plane, a firsteletromagnetic suspension means suspending said first mass, secondelectromagnetic suspension means suspending said second mass, springmeans tending to move said first mass in a predetermined direction andsaid second mass in an opposite direction and a source of currentconnected in series with said first and said second electromagneticsuspension means.

2. A current regulator comprising a first mass mounted for freedom ofmovement along an axis normal to a predetermined plane, a second massmounted for freedom of movement along an axis normal to saidpredetermined plane, a first means including a first voice coilelectromagnetically suspending said first mass, second means including asecond voice coil electromagnetically suspending said second mass, servomeans energizing said first and said second voice coils to maintain saidfirst and said second mass substantially undefiected with respect to itsenvironment, spring means tending to move said first mass in apredetermined direction, and said second mass in an opposite directionand a source of current connected in series with said first and saidsecond voice coils.

3. A current regulator comprising a first mass mounted for freedom ofmovement in a direction normal to a predetermined plane, a second massmounted for freedom of movement in a direction normal to saidpredetermined plane, a first electromagnetic suspension means includinga first air gap, a first voice coil mounted on said mass and positionedin said air gap, second electromagnetic means including a second air gapand a voice coil connected to said second mass and positioned in saidsecond air gap, a first servo means energizing said first voice coil tomaintain said first mass substantially undefiected with respect to itsenvironment, second servo means energizing said second voice coil tomaintain said second mass substantially undefiected with respect to itsenvironment, spring means tending to move said first mass in apredetermined direction and said second mass in an opposite directionand a source of current connected in series with said first and saidsecond voice coils.

4. A current regulator comprising a first mass mounted for freedom ofmovement along an axis normal to a predetermined plane, a second massmounted for freedom of movement along said axis, a first suspensionmeans comprising a first air gap, a voice coil mounted on said firstmass and positioned within said air gap to electromagnetically suspendsaid first mass, a second suspension means comprising a second air gapand a voice coil mounted on said second mass and positioned within saidsecond air gap to electromagnetically suspend said second mass, a springconnected between said first and second masses to provide a mechanicalbasis thereto, a first servo means energizing said first voice coil tomaintain said first mass substantially undefiected with respect to itsenvironment, second servo means energizing said second voice coil tomaintain said second mass substantially undefiected with respect to itsenvironment, said first and said second voice coils connected inparallel a source of current connected in series with said first andsaid second voice coils.

5. A current regulator as set forth in claim 4 including a first fieldcoil for producing said first air gap, a second field coil for producingsaid second air gap, and said first and said second field coils beingconnected in series relationship with said first and said second voicecoils.

6. A current regulator comprising a first mass mounted for freedom ofmovement along a predetermined axis, a second mass mounted for freedomof movement along said axis, first means comprising a voice coil mountedon said first mass, a first air gap, said first voice coil mountedwithin said air gap to electromagnetically suspend said first mass, asecond air gap, a second voice coil mounted on said second mass andpositioned within said second air gap to electromagnetically suspendsaid second mass, spring connected between said first and said secondmasses tending to displace said masses in opposite directions outwardlyof the respective air gaps, a first servo means energizing said firstvoice coil to maintain said first mass substantially undefiected withrespect to its environment, second servo means energizing said secondvoice coil to maintain said second mass substantially undefiected withrespect to its environment, a source of direct current, said sourceconnected to one end of said first and said second voice coils tendingto move said first and said second masses in opposite directions, saidvoice coils being connected in parallel circuit configuration and saidparallel circuit configuration being connected in series with a load.

7. A current regulator as set forth in claim 6 including a first fieldcoil for producing said first air gap, at second field coil forproducing said second air gap, in wherein said parallel circuitconfiguration, said first field coil, said second field coil and saidload are connected in series.

References Cited UNITED STATES PATENTS 2,286,820 6/1942 Lenehan 323-1 X2,657,353 10/1953 Wiancko 323-72 X JOHN F. COUCH, Primary Examiner. G.GOLDBERG, Assistant Examiner.

6. A CURRENT REGULATOR COMPRISING A FIRST MASS MOUNTED FOR FREEDOM OF MOVEMENT ALONG A PREDETERMINED AXIS, A SECOND MASS MOUNTED FOR FREEDOM OF MOVEMENT ALONG SAID AXIS, FIRST MEANS COMPRISING A VOICE COIL MOUNTED ON SAID FIRST MASS, A FIRST AIR GAP, SAID FIRST VOICE COIL MOUNTED WITHIN SAID AIR GAP TO ELECTROMAGNETICALLY SUSPEND SAID FIRST MASS, A SECOND AIR GAP, A SECOND VOICE COIL MOUNTED ON SAID SECOND MASS AND POSITIONED WITHIN SAID SECOND AIR GAP TO ELECTROMAGNETICALLY SUSPEND SAID SECOND MASS, SPRING CONNECTED BETWEEN SAID FIRST AND SAID SECOND MASSES TENDING TO DISPLACE SAID MASSES IN OPPOSITE DIRECTIONS OUTWARDLY OF THE RESPECTIVE AIR GAPS, A FIRST SERVO MEANS ENERGIZING SAID FIRST VOICE COIL TO MAINTAIN SAID FIRST MEANS SUBSTANTIALLY UNDEFLECTED WITH RESPECT TO ITS ENVIRONMENT, SECOND SERVO MEANS ENERGIZING SAID SECOND VOICE COIL TO MAINTAIN SAID SECOND MASS SUBSTANTIALLY UNDEFLECTED WITH RESPECT TO ITS ENVIRONMENT, A SOURCE OF DIRECT CURRENT, SAID SOURCE CONNECTED TO ONE END OF SAID FIRST AND SAID SECOND VOICE COILS TENDING TO MOVE SAID FIRST AND SAID SECOND MASSES IN OPPOSITE DIRECTIONS, SAID VOICE COILS BEING CONNECTED IN PARALLE CIRCUIT CONFIGURATION AND SAID PARALLEL CIRCUIT CONFIGURATION BEING CONNECTED IN SERIES WITH A LOAD. 